I'm going nut with a running HOT issue. No boil over--just running very hot. After hitting 210 it starts running crappy. Block is a 51 Ford 239cu in, Fenton Heads and twin carbs. Hot tanked and magnafluxed. Isky Max-1 Cam. Radiator is aluminum 2 rows of 1" tubes. Running NOS 1948 thermostats. Electric Fan thermostaticaly controlled at 180 degrees. 16 pound prerssure cap. Have already done an Oxalic Acid flush. After 30 minutes of driving it will run up to 210 degrees. Once its up there it won't come back. I am at my wits end. HELP !!!!!!!!!!